In process measurements technology and in laboratory applications, the measuring and monitoring of the physical or chemical parameters of process media or media used in laboratory experiments plays an important role. Such parameters are, for example, pH value, temperature, conductivity, redox potentials, turbidity, oxygen concentration or oxygen partial pressure, ion concentrations, nutrient concentrations, nitrate or chlorine concentrations or concentrations other of chemical compounds. Frequently, sensor modules that must be maintained from time to time are used for measuring these and other parameters. After a maintenance procedure, such as a regenerating, calibration or adjusting, the sensor modules can be used further.
Many such sensor modules are applied in a process in industry, for example, the chemical industry, food technology and the pharmaceuticals industry. The sensor modules are frequently connected to a superordinated unit, for example, a measurement transmitter or a bus coupler, which is arranged near the measuring point and serves for the operation of the sensor unit and for registering, representing, or outputting and, in given cases, forwarding the measurement results to a process control system. Here, there is the need for a function monitoring of each of these sensor modules in order to assure that required maintenance measures can be planned and performed sufficiently early that, at any time, adequate accuracy of measurement of the sensor modules is assured and the process to be controlled by the sensor modules is not endangered. In many areas, especially the food industry and pharmaceuticals industry, it is required, moreover, to have detailed documentation of all aspects of a production process. This also includes the documentation of both the function monitoring as well as the maintenance measures for sensor modules, which are used for monitoring and checking the production process. Furthermore, in the servicing and maintaining of the sensor modules, the risk of servicing errors should be as small as possible.
Maintenance measures, especially such as calibration and/or adjusting, for the sensor modules are frequently not performed directly at the measuring point, at which the respective sensor modules are applied in a process, but centrally in the laboratory.
A measuring system having a superordinated control unit and at least one intelligent field device, which can be, for example, a sensor module, connectable to the control unit is known from DE 20 2010 016 362 U1; this measuring system can be used, on the one hand, for performing measurements by means of the field device, and on the other hand, for performing calibrations on the field device and/or adjusting the field device. Associated with the control unit is at least one interface with a connection element for accommodating a corresponding connection counterpart, wherein the connection counterpart is associated with an interface module, wherein associated with the interface module is a software protection system securing access to the field device, wherein the interface module permits communication between the corresponding field device and the superordinated control unit, wherein associated with the superordinated control unit is a software protected editing program for the field device, and wherein the editing program is started or enabled via the software protection system when the connection counterpart of the interface module of the field device is connected to the connection element of the control unit. As soon as the interface module is connected to the control unit, the editing program associated with the field device starts. The editing program is embodied to graphically represent measurement data transmitted by the field device on a display of the control unit or to execute a parametering/configuring of the field device via the control unit. The measuring system of DE 20 2010 016 362 U1 also permits, for calibration purposes, the connection, in addition to the actual field device, of a reference field device for reviewing the measured values of the actual field device.
US 2009/0287445 A1 describes a system for calibration and function checking a sensor system used in a process. The sensor system can be a measuring probe with a sensor module, a memory system and an electronic input/output interface, wherein the memory system communicates both with the sensor module as well as with the input/output interface. The sensor module can be connected to a PC, which is arranged remotely from the process, or to a measurement transmitter arranged near the process. The PC can utilize operating software for calibration and function checking the sensor module. Both the measurement transmitter as well as the operating software can access a central database, in which information on sensor modules is stored. The operating software is embodied to calibrate the sensor module connected to the PC. For this, a user must handle the sensor module to be calibrated, for example, to clean and to immerse it in at least one calibration medium, on the one hand, and, on the other hand, to input a series of calibration parameters, for example, the identification numbers of the calibration media used for calibration, in an entry form of the operating program. In more complex calibration procedures, for example, in calibrations, which include the registering of a series of measurement points in different calibration and/or reference media, errors can easily occur with a user lacks sufficient training or experience. Likewise, errors can occur in the inputting of parameters of the calibration media or sensor specific data. Moreover, inputting data or setup information in an operating program requires a certain expenditure of time.